7.8

CVE-2021-20194: linux linux_kernel Improper Input Validation

Modified
AliasesUBUNTU-CVE-2021-20194DEBIAN-CVE-2021-20194CGA-2392-42cf-88p7
Published 23-02-2021Last modified 03-08-2024

Vulnerability summary

CVE-2021-20194 is a high (CVSS 7.8) Improper Input Validation vulnerability in linux linux_kernel. EPSS estimates a 0.40% chance of exploitation in the next 30 days, higher than 34.2% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 7.8, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
7.8/10
010
High · v3.1 (NVD)
EPSS score
0.40%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 8 · Related 5
MGASA-2021-0099MGASA-2021-0100RHSA-2021:4140RHSA-2021:4356USN-4879-1USN-4884-1

Timeline

  1. 23-02-2021
    PublishedVulnerability first disclosed.
  2. 03-08-2024
    Last modifiedVulnerability information updated.

Description

There is a vulnerability in the linux kernel versions higher than 5.2 (if kernel compiled with config params CONFIG_BPF_SYSCALL=y , CONFIG_BPF=y , CONFIG_CGROUPS=y , CONFIG_CGROUP_BPF=y , CONFIG_HARDENED_USERCOPY not set, and BPF hook to getsockopt is registered). As result of BPF execution, the local user can trigger bug in __cgroup_bpf_run_filter_getsockopt() function that can lead to heap overflow (because of non-hardened usercopy). The impact of attack could be deny of service or possibly privileges escalation.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.40%

Chance of exploitation in the next 30 days

Percentile

34%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.40% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Chainguard83 products
  • hyperv-daemons-6.18All versions (No fix recorded)
  • hyperv-daemons-genericAll versions (No fix recorded)
  • linux-aws-6.12< 6.12.65-r0 | All versions (No fix recorded)
  • linux-aws-6.12-boot-installedAll versions (No fix recorded)
  • linux-aws-6.12-fips-boot-installedAll versions (No fix recorded)
Ubuntu41 products
  • linux< 5.4.0-71.79
  • linux-aws< 5.4.0-1043.45
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.3All versions (No fix recorded)
  • linux-aws-5.4< 5.4.0-1043.45~18.04.1
Redhat2 products
Debian1 product
  • linux< 5.10.19-1
Linux1 product

5 vendors · 128 products

References

11 links
Show all 11 references